Method for producing a photovoltaic module by means of resin transfer moulding

Abstract

The invention relates to a method for producing a photovoltaic module (10), wherein the photovoltaic module (10) comprises a first layer (12), a second layer (14) and at least one photovoltaic cell (16); the production method comprising a step of installing an initial stack (28) in an assembly mould (20), the assembly mould comprising a rigid first mould portion (22) delimiting a first imprint (220) having a shape complementary to the shape of the first layer (12) and a rigid second mould portion (24) delimiting a second imprint (240) having a shape complementary to the shape of the second layer (14), the first mould portion (22) and the second mould portion (24) delimiting between them a closed cavity (30), the production method comprising a resin transfer moulding step E2 in which a resin in the liquid state is injected into the cavity (30).

Description

[0001] DESCRIPTION

[0002] TITLE: Manufacturing process of a photovoltaic module using resin transfer molding

[0003] Technical field of the invention

[0004] The present invention relates to the field of manufacturing photovoltaic modules, which comprise a set of photovoltaic cells electrically connected to each other, and preferably so-called "crystalline" photovoltaic cells, i.e. which are based on monocrystalline or multicrystalline silicon, and in particular a photovoltaic module without a glass plate, light and rigid, with the possibility of being shaped into a lopsided form.

[0005] More specifically, the invention relates to a method of manufacturing a photovoltaic module.

[0006] The invention can be implemented for numerous applications, in particular civil and / or military, for example autonomous and / or embedded applications, being particularly concerned by applications which require the use of photovoltaic modules without glass plate and light, in particular of non-planar shape, and of low thickness, in particular less than 5 mm. It can thus in particular be applied for buildings such as homes or industrial premises (tertiary, commercial, etc.), for example for the construction of their roofs, for the design of street furniture, for example for public lighting, road signs or even the recharging of electric cars, or even be used for nomadic applications (solar mobility), in particular for integration on vehicles, such as cars, buses or boats, drones, airships, among others.

[0007] In the rest of the document, a so-called left-handed shape is a non-planar, curved, incurved, domed or hollow shape, and more generally presenting a general three-dimensional shape not oriented along a principal plane.

[0008] State of the art

[0009] A photovoltaic module is an assembly of photovoltaic cells arranged side by side between a first transparent layer forming a front face of the photovoltaic module and a second layer forming a rear face of the photovoltaic module. The first layer forming the front face of the photovoltaic module is advantageously transparent to allow the photovoltaic cells to receive a luminous flux. It is traditionally made from a single glass plate, in particular tempered glass, with a thickness typically between 2 and 4 mm, conventionally of the order of 3 mm.

[0010] The second layer forming the rear face of the photovoltaic module can be made from glass, metal or plastic, among others. It is often formed by a polymeric structure based on an electrically insulating polymer, for example of the polyethylene terephthalate (PET) or polyamide (PA) type, which can be protected by at least one layer based on fluorinated polymers, such as polyvinyl fluoride (PVF) or polyvinylidene fluoride (PVDF), and having a total thickness of around 300-400 pm.

[0011] The photovoltaic cells can be electrically connected to each other by front and rear electrical contact elements, called connecting conductors, and formed for example by strips of tinned copper, respectively arranged against the front faces (faces facing the front face of the photovoltaic module intended to receive a luminous flux) and rear faces (faces facing the rear face of the photovoltaic module) of each of the photovoltaic cells, or even only on the rear face for photovoltaic cells of the type known by the acronym IBC.

[0012] It should be noted that IBC type photovoltaic cells are structures for which the contacts are made on the rear face of the cell in the form of combs whose fingers are interconnected. They are for example described in document US4478879A.

[0013] Furthermore, the photovoltaic cells, located between the first and second layers forming respectively the front and rear faces of the photovoltaic module, can be encapsulated. Conventionally, the chosen encapsulant corresponds to a polymer of the elastomer (or rubber) type, and can for example consist of the use of two layers (or films) of poly(ethylene-vinyl acetate) (EVA) between which the photovoltaic cells and the cell connecting conductors are arranged. Each layer of encapsulant can have a thickness of at least 0.2 mm and a Young's modulus typically between 2 and 400 MPa at room temperature.

[0014] It is thus partially and schematically represented, respectively in section in figure 1 and in exploded view in figure 2, a known example of photovoltaic module 1 comprising crystalline photovoltaic cells 4.

[0015] As described above, the photovoltaic module 1 comprises a front face 2, generally made of transparent tempered glass with a thickness of approximately 3 mm, and a rear face 5, for example made of a polymer sheet, opaque or transparent, single-layer or multi-layer, having a Young's modulus greater than 400 MPa at room temperature.

[0016] Between the front 2 and rear 5 faces of the photovoltaic module 1 are the photovoltaic cells 4, electrically connected to each other by connecting conductors 6 and immersed between two front 3a and rear 3b layers of encapsulating material, both forming an encapsulating assembly 3.

[0017] Figure 1A further represents an alternative embodiment of the example of Figure 1 in which the photovoltaic cells 4 are of the IBC type, the connecting conductors 6 being arranged only against the rear faces of the photovoltaic cells 4.

[0018] Furthermore, figures 1 and 2 also represent the junction box 7 of the photovoltaic module 1, intended to receive the wiring necessary for the operation of the photovoltaic module 1. Conventionally, this junction box 7 is made of plastic or rubber, and has complete sealing.

[0019] Usually, the manufacture of the photovoltaic module 1 includes a step called vacuum lamination of the different layers described above, at a temperature greater than or equal to 120°C, or even 140°C, or even 150°C, and less than or equal to 170°C, typically between 145 and 165°C, and for a duration of the lamination cycle of at least 10 minutes, or even 15 minutes.

[0020] During this lamination step, the layers of encapsulation material 3a and 3b undergo fusion and come to encompass the photovoltaic cells 4, at the same time as adhesion is created at all the interfaces between the layers, namely: between the front face 2 and the front layer of encapsulation material 3a, between the front layer of encapsulation material 3a and the front faces 4a of the photovoltaic cells 4, between the rear faces 4b of the photovoltaic cells 4 and the rear layer of encapsulation material 3b, between the rear layer of encapsulation material 3b and the rear face 5 of the photovoltaic module 1.

[0021] It is the adhesion between these different components which allows the assembly of the photovoltaic module 1 to be carried out, being a product which is then in one piece which is then framed, typically using a frame using aluminium profiles.

[0022] Such a structure has now become a standard which has significant mechanical resistance thanks to the use of a front face 2 made of thick glass and the aluminum frame, allowing it, in particular and in the majority of cases, to comply with the IEC 61215 and IEC 61730 standards. Nevertheless, such a photovoltaic module 1 has the essential disadvantage of having a high mass, in particular a mass per unit area (or surface mass) of approximately 10 to 12 kg / m 2 , making it unsuitable for applications where lightness is a priority.

[0023] This high mass of the photovoltaic module 1 comes mainly from the presence of thick glass, with a thickness of approximately 3 mm, to form the front face 2, the density of the glass being in fact high, of the order of 2.5 kg / m 2 / mm thick, and the aluminum frame. To be able to withstand the stresses during manufacturing and also for safety reasons, for example due to the risk of cuts, the glass is tempered. However, the industrial infrastructure for thermal tempering is configured to process glass at least 2 mm thick. In addition, the choice of having a glass thickness of approximately 3 mm is also linked to a standardized mechanical resistance to pressure of 5.4 kPa. Ultimately, the glass alone represents almost 70% of the mass of the photovoltaic module 1 , and more than 80% including the aluminum frame.

[0024] Also, in order to obtain a significant reduction in the mass of a photovoltaic module to allow its use in new applications requiring lightness and shaping, attempts have already been made to find an alternative solution to the use of thick glass on the front face of the photovoltaic module, by using new plastic or composite materials with the main aim of obtaining a significant reduction in the surface mass.

[0025] Thus, unreinforced thermoplastic sheets of polymer type such as polycarbonate (PC), polymethyl methacrylate (PMMA), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), or fluorinated ethylene propylene (FEP), can represent an alternative to glass. However, when only the replacement of glass by such a thin polymer sheet is considered, the photovoltaic cell becomes very vulnerable to shock, mechanical load and differential expansion.

[0026] Another alternative is the use, at least on the front face, of composite materials based on at least one reinforcement and a thermosetting resin, replacing standard glass. The weight saving can be significantly significant at the cost of reduced transparency.

[0027] To meet the challenges of weight savings, the processes most commonly used exploit the principles of hot vacuum lamination, or more rarely the principles of infusion.

[0028] In the lamination technique, the first and second layers forming the front and rear faces of the photovoltaic module are at least partially manufactured at the same time as the encapsulating assembly is formed and a tarpaulin is present to apply a homogeneous pressure during pressurization of the stack. The implementation of such techniques for lopsided shapes would present great difficulties because the application of a homogeneous pressure by the tarpaulin on a stack of non-homogeneous thickness, due to a phenomenon of creep of the encapsulating material towards low points of the mold resulting from the heating conditions, would inevitably lead to obtaining a photovoltaic module having a non-homogeneous thickness.

[0029] Vacuum infusion molding, or simply infusion, is a traditional technique for processing composite materials. It involves placing dry reinforcements under vacuum in a mold closed by a tarpaulin, which are then impregnated with the arrival of resin, which is sucked in by the vacuum created between the tarpaulin and the mold. This type of process is unfortunately not industrializable due to its low production rate and the fact that it cannot be automated.

[0030] Among the known manufacturing processes, the following patent documents can be cited, for example:

[0031] WO2021107334A1 which relates to a method for manufacturing photovoltaic modules in an autoclave based on pre-pregs;

[0032] CN210807135U which describes flexible photovoltaic modules for a solar car, with a polycarbonate front face;

[0033] CN211 166388U and CN111391625A which describe flexible photovoltaic modules for a solar car;

[0034] KR101423245B1 which describes a method of injecting resin into a mold, with cells;

[0035] FR3052595A1 which describes a lamination of pre-pregs with honeycomb;

[0036] JPH0485970A which describes pressure lamination of carbon prepregs for integration into photovoltaic panels;

[0037] W02018060611A1 which describes an encapsulation of photovoltaic cells in epoxy resin pre-pregs;

[0038] US20170250299A1 which describes an encapsulation of photovoltaic cells with a front face made of composite material;

[0039] FR2934418A1 which describes a single-step encapsulation of photovoltaic cells by infusion;

[0040] W02018060611A1 which describes an encapsulation of photovoltaic cells with a thermosetting pre-preg. However, beyond the weight reduction issues presented above, mechanical strength issues should be added. Thus, to obtain optimal mechanical properties, the implementation of composite materials can require significant pressures, typically between 10.10 5 Pa and 60.10 5Pa. Furthermore, while thermosetting composite materials (-similar to non-recyclable materials) have the advantage of being able to be implemented at temperatures generally below 100°C, thermoplastic materials are, on the other hand, implemented at much higher temperatures, typically between 150 and 250°C. These two temperature and pressure constraints, necessary for the mechanical strength of the composite materials obtained, complicate the implementation of photovoltaic modules composed of composite materials at the level of the first and second layers respectively on the front and rear faces. Indeed, the encapsulation materials used in the architectures conforming to Figure 1 have implementation properties that are difficult to reconcile with these pressure and temperature levels, due to their tendency to creep.This creep increases the risk of displacements which could lead to the deterioration or rupture of photovoltaic cells or the connections between these cells, particularly in the case of the use of silicon photovoltaic cells.

[0041] Furthermore, none of these currently known solutions makes it possible to achieve the manufacture of a photovoltaic module which, in addition to being light (therefore without glass) and resistant as required by the needs of numerous concrete applications and administrative standards such as IEC 61215 and IEC 61730, can be spatially shaped according to a left shape, in particular typically shaped with a curvature which can be identical or different along two distinct axes of a reference associated with the photovoltaic module, and moreover produced in a simple, rapid, efficient and economical manner, and ideally using only recyclable materials.

[0042] Subject of the invention

[0043] The invention therefore aims to at least partially remedy the needs mentioned above and the drawbacks relating to the achievements of the prior art.

[0044] In particular, there is a need to propose a manufacturing process for photovoltaic modules that are lightweight and suitable for meeting the mechanical strength requirements that depend on practical applications and administrative standards such as IEC 61215 and IEC 61730, where the manufacturing process is simple, fast, efficient, economical, offering the possibility of using recyclable materials, allowing automation and a good production rate, compatible with the production of photovoltaic modules of left shape, which offers the opportunity for optimal resin injection pressure and temperature conditions for the mechanical strength of the photovoltaic module, with a possibility of integrating encapsulation materials while avoiding the risks of creep of the latter during the injection of the resin.

[0045] The subject of the invention is thus a method for manufacturing a photovoltaic module where the photovoltaic module comprises: a first layer formed in a first composite material, transparent, intended to form a front face of the photovoltaic module and to receive a luminous flux, a second layer formed in a second composite material and intended to form a rear face of the photovoltaic module, and at least one photovoltaic cell located between the first layer and the second layer, the manufacturing method comprising the following steps:

[0046] E1) placing an initial stack in an assembly mold, where the initial stack comprises the superposition of the following elements: at least one first dry reinforcement intended to belong to the first layer and to enter into the composition of the first composite material, said at least one photovoltaic cell, at least one second dry reinforcement intended to belong to the second layer and to enter into the composition of the second composite material, the initial stack being such that the plurality of photovoltaic cells is located between the at least one first dry reinforcement and the at least one second dry reinforcement,the assembly mold having an ability to vary between an opening configuration and a closing configuration and comprising a first rigid mold part delimiting a first imprint having a shape complementary to the shape of the first layer and a second rigid mold part delimiting a second imprint having a shape complementary to the shape of the second layer, the first mold part and the second mold part being such that, in the closing configuration of the assembly mold, the first mold part and the second mold part are spaced apart by a predetermined air gap preferably greater than or equal to the thickness of the initial stack, and delimit between them a closed cavity capable of receiving the initial stack,

[0047] E2) resin transfer molding, in which a resin in the liquid state is injected into the cavity in such a way that the resin passes through the at least one first dry reinforcement and through the at least one second dry reinforcement,

[0048] E3) curing of the resin injected in step E2, step E3 being carried out by a suitable adjustment of the temperature prevailing in the cavity, depending on the nature of the resin, the combination of the at least one first dry reinforcement and the resin in the hardened state at the end of step E3 constituting said first composite material and the combination of the at least one second dry reinforcement and the resin in the hardened state at the end of step E3 constituting said second composite material.

[0049] Some preferred but not limiting aspects are as follows.

[0050] According to one embodiment, the initial stack comprises at least one encapsulation material, the initial stack being such that the at least one encapsulation material is located between the at least one first dry reinforcement and the at least one second dry reinforcement. During step E2, the temperature of the resin is adapted as a function of the at least one encapsulation material so that the at least one encapsulation material undergoes at least partial melting under the effect of calories transmitted by the resin and converts the at least one encapsulation material into an encapsulating assembly adhering on the one hand to the at least one photovoltaic cell and on the other hand to the first layer and / or to the second layer.

[0051] According to one embodiment, the first imprint has a first shape such that the first layer is shaped according to a first left shape at the end of step E3 and the second imprint has a second shape such that the second layer is spatially shaped according to a second left shape at the end of step E3.

[0052] According to one embodiment, step E2 comprises, after step E1, the following steps:

[0053] E21) depression applied to the cavity delimited by the assembly mold in the closed configuration, relative to the pressure prevailing outside the cavity, E22) injection of the resin into the cavity in a pressurized manner at a pressure strictly greater than the pressure prevailing in the cavity, step E22 being carried out after step E21.

[0054] According to one embodiment, step E2 comprises a step E20 of heating the resin carried out prior to the implementation of step E22.

[0055] According to one embodiment, step E22, the injection of the resin is carried out in a directed manner following a preferential direction in which the resin preferentially circulates inside the cavity delimited by the assembly mold.

[0056] According to one embodiment, the assembly mold comprises at least one discharge outlet in fluid connection with a suction system making it possible to establish a vacuum in the cavity delimited by the assembly mold.

[0057] According to one embodiment, the assembly mold comprises at least one supply inlet in fluid connection with a supply system making it possible to inject the resin towards the cavity delimited by the assembly mold. According to one embodiment, at the end of step E1, the at least one supply inlet and the at least one discharge outlet are located on either side of the initial stack in a first direction oriented along said preferred direction.

[0058] According to one embodiment, the assembly mold comprises at least one first draining medium into which the at least one feed inlet opens, said first draining medium ensuring drainage of the resin in a second direction oriented transversely to the first direction.

[0059] According to one embodiment, the assembly mold comprises at least one second draining medium into which the at least one evacuation outlet opens, said second draining medium ensuring drainage of the resin in a second direction oriented transversely to the first direction.

[0060] According to one embodiment, in step E21, the pressure established in the cavity is between 0.5.10 5 Pa and 1.10 5 Pa.

[0061] According to one embodiment, during step E22, the injection of the resin is controlled so that the pressure prevailing in the cavity delimited by the assembly mold is between 2.10 5 Steps and 50.10 5 Pa.

[0062] According to one embodiment, the resin is a thermoplastic resin.

[0063] According to one embodiment, step E3 comprises a step of lowering the temperature of the stack resulting from step E2 compared to the conditions present during step E2.

[0064] According to one embodiment, the resin is a thermosetting resin.

[0065] According to one embodiment, step E3 comprises a step of maintaining or increasing the temperature of the stack resulting from step E2 relative to the conditions present during step E2.

[0066] According to one embodiment, the first mold part and the second mold part of the assembly mold exert, on the stack, mechanical pressure during all or part of step E2 and during all or part of step E3.

[0067] According to one embodiment, the mechanical pressure is between 90.10 5 Pa and 150.10 5 Pa, and more particularly equal to 90.10 b Pa, or equal to 150.10 5 Pa.

[0068] According to one embodiment, the manufacturing method comprises a step E4 of opening the assembly mold in which the assembly mold passes from the closing configuration to the opening configuration, step E4 being implemented after step E3.

[0069] According to one embodiment, during step E1, the initial stack further comprises the superposition of a junction box intended to receive wiring necessary for the operation of the photovoltaic module. Brief description of the drawings

[0070] Other aspects, aims, advantages and characteristics of the invention will appear better on reading the following detailed description of preferred embodiments thereof, given by way of non-limiting example, and made with reference to the appended drawings in which: Figure 1 represents, in section, a classic example of a photovoltaic module comprising crystalline photovoltaic cells, according to the state of the art.

[0071] Figure 1A represents an alternative embodiment of the example of Figure 1 in which the photovoltaic cells are of the IBC type.

[0072] Figure 2 shows, in exploded view, the photovoltaic module of Figure 1.

[0073] Figure 3 represents, in the form of a flowchart, different stages of an example of a manufacturing method according to the invention.

[0074] Figure 4 represents, in perspective, an example of a photovoltaic module which can be obtained by implementing a manufacturing process according to the steps of Figure 3.

[0075] Figure 5 represents, in perspective, an example of an assembly mold capable of being used for implementing a manufacturing process according to the steps of Figure 3.

[0076] Figure 6 is a sectional view of the assembly mold, in a plane oriented along the first and second directions, schematically displaying the circulation of the resin.

[0077] Figure 7 represents a first curve illustrating an example of evolution, with different successive phases P1 to P4, of the temperature adopted by the part to be produced as a function of time in a first example of manufacturing method according to the invention.

[0078] Figure 8 schematically represents the behavior of the assembly mold and the stack during an initial first phase PO then during the different phases P1 to P4 corresponding to those defined in figure 7.

[0079] Figure 9 represents a second curve illustrating an example of evolution, with different successive phases P1 to P4, of the temperature adopted by the part to be produced as a function of time in a second example of manufacturing process according to the invention using a thermosetting resin.

[0080] Figure 10 schematically represents the behavior of the assembly mold and the stack during an initial first phase PO then during the different phases P1 to P4 corresponding to those defined in figure 9.

[0081] Detailed Description Figures 1, 1A and 2 have already been described in the section relating to the state of the prior art.

[0082] Figure 3 represents, in the form of a flowchart, the different stages of an example of a manufacturing method according to the invention.

[0083] The implementation of these steps allows for example the obtaining of a photovoltaic module 10, an example of which is shown in figure 4, having the particularity of having a general lopsided, non-planar shape, this term “lopsided shape” having been previously defined in the part relating to the state of the art.

[0084] It is emphasized that, even if the method advantageously makes it possible to manufacture a photovoltaic module 10 of lopsided shape in a simple, economical, efficient and rapid manner, it remains possible to envisage applying its teachings to manufacture a photovoltaic module of planar shape. By planar shape, it is meant that each of the first layer 12 and the second layer 14 is shaped without having any curvature along an axis of a reference which would be associated with the photovoltaic module 10, ultimately corresponding to a general parallelepiped shape.

[0085] The photovoltaic module 10 which can be obtained using the manufacturing method described in the present document comprises for example at least: a first layer 12 having a lopsided shape, formed in a first composite material, transparent and intended to form a front face of the photovoltaic module 10 intended to receive a luminous flux, a second layer 14 having a lopsided shape, formed in a second composite material, and intended to form a rear face of the photovoltaic module 10, at least one photovoltaic cell located between the first layer 12 and the second layer 14, an encapsulating assembly 18 ensuring encapsulation of all or part of the photovoltaic cells 16.

[0086] Generally, said at least one photovoltaic cell 16 comprises a plurality of photovoltaic cells 16 arranged side by side, and electrically connected to each other. Thus, and to simplify the remainder of the description, reference will be made to a plurality of photovoltaic cells 16, although it is possible to use the terms “at least one photovoltaic cell 16” indifferently instead.

[0087] According to a first embodiment, the first composite material is different from the second composite material.

[0088] According to a second embodiment, the first composite material is identical to the second composite material. Generally, each of the first composite material and the second composite material comprises at least one dry reinforcement, and one resin. As will be described later, it is possible to use a different dry reinforcement (by its structure, its nature or its composition) between the first composite material and the second composite material, and an identical resin for the first composite material and the second composite material. In this way, it is possible to obtain the first layer 12 and the second layer 14 by a single process step.

[0089] It is specified that if the presence of the encapsulating assembly 18 is advantageous, it nevertheless remains that it is optional, provided then that only the first layer 12, the second layer 14 and the photovoltaic cells 16 are present, these three elements having to be linked together at the end of the process in order to provide a unitary photovoltaic module 10, that is to say a single piece.

[0090] In Figure 4 which represents the particular case of a left shape for the layers 12, 14, the photovoltaic cells 16 and the encapsulating assembly 18 are arranged between the first layer 12 and the second layer 14. This arrangement would also be verified even in the case of a photovoltaic module 10 of planar shape.

[0091] Generally, the first layer 12 is formed as a single monolayer portion and the second layer 14 is also formed as a single monolayer portion.

[0092] The term “transparent” means in this document that the first layer 12 forming the front face of the photovoltaic module 10 is at least partially transparent to visible light, allowing at least approximately 80% of this light to pass through. In particular, the optical transparency, between 400 and 1200 nm, of the first layer 12 may be greater than 80%.

[0093] Referring now to Figure 3, the manufacturing method comprises a step E1 of placing an initial stack 28 in an assembly mold 20, the initial stack 28 comprising the superposition of at least the following elements: at least one first dry reinforcement intended to belong to the first layer 12 at the end of the manufacturing method and to enter into the composition of the first composite material previously defined, one or more photovoltaic cells 16 as already mentioned, at least one second dry reinforcement intended to belong to the second layer 14 at the end of the manufacturing method and to enter into the composition of the second composite material previously defined.

[0094] Within the initial stack 28, the plurality of photovoltaic cells 16 is located between the at least one first dry reinforcement and the at least one second dry reinforcement. What distinguishes the first dry reinforcement and the second dry reinforcement from a semantic point of view is here only the fact of belonging respectively to the first layer 12 and to the second layer 14 once the manufacturing process is finished. Thus, and according to one embodiment, it is possible for the first dry reinforcement to be identical to the second dry reinforcement in terms of its nature, and / or its organization (i.e. the number of folds and their relative orientation), and / or its reinforcement rate.

[0095] However, and alternatively, it is possible that the first dry reinforcement differs from the second dry reinforcement according to one or more of the parameters cited above, that is to say its nature, its organization, or its reinforcement rate.

[0096] According to a particular embodiment, the initial stack 28 comprises at least one encapsulation material 181, 182, the initial stack 28 being such that the at least one encapsulation material 181, 182 is located between the at least one first dry reinforcement and the at least one second dry reinforcement. In this variant, at the end of the manufacturing process, each of the encapsulation materials 181, 182 present will form part of the optional encapsulating assembly 18 already mentioned. The first encapsulation material 181 is placed between the photovoltaic cells 16 and what will become the first layer 12 at the end of the manufacturing process. The second encapsulation material 182 is placed, for its part, between the photovoltaic cells 16 and what will become the second layer 14 at the end of the manufacturing process.

[0097] Furthermore, in the non-limiting embodiment where there is the presence of the encapsulating assembly 18, the term "encapsulating" should be understood to mean that the plurality of photovoltaic cells 16 is then arranged in a volume, for example hermetically sealed against liquids, at least partly formed by at least two layers of encapsulating material(s), joined together, at the end of the manufacturing method which will be described, to form the encapsulating assembly 18.

[0098] Indeed, initially, that is to say before the implementation of step E2 which will be described later, the encapsulating assembly 18 not yet finalized is constituted by at least one layer of the encapsulating material 181, which is then located between the plurality of photovoltaic cells 16 and the at least one first dry reinforcement and / or by at least one layer of the encapsulating material 182, which is then located between the plurality of photovoltaic cells 16 and the at least one second dry reinforcement. However, it is generally during step E2 that this / these encapsulating material(s) 181 and / or 182 will undergo at least partial melting to form, after cooling, the solidified encapsulating assembly 18 in which the photovoltaic cells 16 are then hermetically embedded.

[0099] The implementation of step E1 can be automated via suitable handling robots, manual or semi-automatic. At the time of their implementation, the first and second dry reinforcements are not impregnated with a resin. Once again, even if it can be advantageous, the presence of the encapsulation materials 181, 182 remains optional. In the variant without the encapsulating assembly 18 at the end of the manufacturing method, the at least one first dry reinforcement is, in step E1, in a position to face or be in direct contact with the front face of the photovoltaic cells 16, while the at least one second dry reinforcement is, in step E1, in a position to face or be in direct contact with the rear face of the photovoltaic cells 16.

[0100] By "dry" is meant that each of the first and second reinforcements does not yet comprise resin, unlike products known in the field of composite materials of the pre-impregnated type or of the fiber-reinforced thermoplastic composite plate type (such a plate being an assembly of already compacted composite plies).

[0101] The composition of the first dry reinforcement may be identical to the composition of the second dry reinforcement. Alternatively, the composition of the first dry reinforcement may be different from the composition of the second dry reinforcement. This may depend, for example, on the transparency required for the first layer 12, the mechanical strengths to be obtained, the costs or the need for transparency or not of the second layer 14.

[0102] In step E1, it is possible to provide one or more first dry reinforcement(s). In the case where there are several, they may be superimposed in an organization where all or part of the surface of one of the first dry reinforcements present covers all or part of the surface of another of the first dry reinforcements present. In this case, each first dry reinforcement may be arranged so that a mesh of one of the first dry reinforcements is in the same direction as another first dry reinforcement, or that the superposition of said first dry reinforcements is implemented by providing an angular offset between the meshes of the first dry reinforcements, for example equal to 45° or 90°.

[0103] Similarly, it is possible to provide one or more second dry reinforcement(s). In the case where there are several, they may be superimposed in an organization where all or part of the surface of one of the second dry reinforcements present covers all or part of the surface of another of the second dry reinforcements present. In this case, each second dry reinforcement may be arranged so that a mesh of one of the second dry reinforcements is in the same direction as another second dry reinforcement, or that the superposition of said second dry reinforcements is implemented by providing an angular offset between the meshes of the second dry reinforcements, for example equal to 45° or 90°.

[0104] Each first dry reinforcement and each second dry reinforcement is an element known per se in the technical field of composite materials. It is the reinforcement capable of absorbing the majority of the mechanical forces that will be applied to the first composite material and the second composite material, respectively. The person skilled in the art is perfectly familiar with such reinforcements and knows that they are elements (fibers) in the form of threads, a woven or non-woven web, braids, or a combination of these elements, for example by weaving or twill, or in the form of a web of non-woven loose fibers (mat).To obtain the first composite material in which the first layer 12 is formed as well as the second composite material in which the second layer 14 is formed, after step E1 it is necessary to embed each first dry reinforcement in a resin so that it then polymerizes in the case where the resin has thermoplastic characteristics or so that it then crosslinks in the case where the resin has thermosetting characteristics. The same resin will advantageously be used for the consolidation of the first composite material and the second composite material respectively of the first and second layers 12, 14. This is an advantage in terms of simplicity of implementation as well as ease of management of the resin.Furthermore, the use of a single resin allows for good chemical compatibility between the first layer 12 and the second layer 14, which improves the structural integrity of the photovoltaic module 10.

[0105] The composition of each first dry reinforcement is preferably glass, making it possible to obtain the desired transparency for the first layer 12, in order to allow the light flux intended to be received by the front face of the first layer 12 to pass through and allow the highest possible fraction (approximately 80%) of this light flux to be incident on the underlying photovoltaic cells 16. The composition of each second dry reinforcement may, for its part, in particular be chosen from glass, carbon, aramid, natural fibers chosen from hemp, linen, silk among others.

[0106] Typically, each of the first and second dry reinforcements may have a matt or woven arrangement, for example twill (this is a woven reinforcement that has fine oblique ribs), or triaxial or quadriaxial, or non-woven. The sizing (this is the surface treatment of the reinforcement intended to facilitate subsequent operations), the composition, the arrangement or even the length (the shape including as a parameter whether the fibers are short (0.1 to 1 mm), long (1 to 50 mm) or continuous (greater than 50 mm), or even the possible presence of reinforcing fillers) of each first dry reinforcement and each second dry reinforcement may be adapted according to criteria such as the transparency to be obtained, the mechanical strength to be obtained, the cost, the surface mass and / or the thickness of the photovoltaic module 10.It is particularly preferable to optimize the transparency of the first composite material in which the first layer 12 is formed.

[0107] In a particular non-limiting example which gives satisfaction in the tests and simulations, the presence of three first dry reinforcements superimposed on each other may be provided. According to one embodiment, the first dry reinforcements are superimposed so that they are oriented in the direction of flow, or at 45° relative to the direction of flow of the resin during step E2 which will be described later. These first dry reinforcements have a twill-type arrangement, each having a glass composition and a surface mass of 285 g / m 2, advantageously conferring very good transparency to the first layer 12 to be obtained subsequently. The presence of three second dry reinforcements superimposed on each other, having a twill-type arrangement, each having a glass composition and a surface mass of 285 g / m 2 These reinforcements can be used in steps E2, E3 described below in combination with a polyepoxide type resin, also called epoxy polymer or commonly “epoxy”. At the end of step E3, the first layer 12 which has a thickness of less than 2 mm, preferably of the order of 0.5 mm, can then have a surface mass of between 120 and 200 g / m 2 , and preferably of the order of 160 g / m 2for reasons of lightness and size. At the end of step E3, the second layer 14 which has a thickness of less than 2 mm, preferably of the order of 0.5 mm, may also have a mass per unit area of ​​between 120 and 200 g / m 2 , and preferably of the order of 160 g / m 2 for reasons of lightness and size.

[0108] In the example of Figure 4, the first layer 12 is shaped according to a curvature which may be identical or different along two distinct axes of a reference frame associated with the photovoltaic module 10. In a complementary manner, the second layer 14 is shaped according to a curvature which may be identical or different along two distinct axes of a reference frame associated with the photovoltaic module 10. According to one embodiment, the curvatures are identical for the first layer 12 and for the second layer 14. Thus, and advantageously, it is possible to guarantee a complementarity of shapes for the first and second layers 12, 14, and to obtain a homogeneity of thickness of the first layer 12, and of the second layer 14.

[0109] The photovoltaic cells 16 may be chosen from: homojunction or heterojunction photovoltaic cells based on monocrystalline silicon (c-Si) and / or multicrystalline silicon (mc-Si), and / or IBC type photovoltaic cells, and / or photovoltaic cells comprising at least one material from amorphous silicon (a-Si), microcrystalline silicon (pC-Si), cadmium telluride (CdTe), copper-indium selenide (CIS) and copper-indium / gallium diselenide (CIGS), perovskites, among others.

[0110] The photovoltaic cells 16 are interconnected with each other, for example in the form of a garland along a strip. The spacing between two neighboring, or consecutive or adjacent, photovoltaic cells 16 may be greater than or equal to 1 mm, in particular between 1 and 30 mm, and preferably equal to 2 mm. The use of connectors with increased mechanical resistance may be envisaged, depending on the applications and in particular depending on the pressure to which they must resist.

[0111] Step E1 may therefore comprise an initial step consisting of interconnecting the photovoltaic cells 16 with each other, in order to constitute an interconnected assembly capable of being put in place between the at least one first dry reinforcement and the at least one second dry reinforcement. In the case where there is the presence of encapsulation materials 181, 182 for example intended to undergo at least partial melting under the effect of the supply of calories by the resin injected in the subsequent step E2, then this interconnected assembly will be put in place between the encapsulation materials 181, 182 during said initial step.

[0112] Furthermore, the photovoltaic cells 16 may have a thickness of between 1 and 300 pm, in particular between 1 and 200 pm, and advantageously between 70 pm and 160 pm if they are based on crystalline silicon, making it possible to limit the weight and size.

[0113] The photovoltaic module 10 may further comprise a junction box 7 (not visible in FIG. 4), intended to receive the wiring necessary for the operation of the photovoltaic module 10 and which may be positioned on the front face or on the rear face of the photovoltaic module 10, preferably on the front face. The manner of producing this junction box is not limiting in itself and any known technique may be used. It may for example be an organization incorporating the teachings and principles of FIGS. 1, 1A and 2. For example, the junction box 7 may be integrated into the initial stack 28 during step E1 of setting up the initial stack. Thus, the junction box 7 may be superimposed with the other elements of the initial stack 28 so that it is integrated into the photovoltaic module 10 at the time of the molding step E2.

[0114] The assembly mold 20 in which the initial stack 28 is placed during step E1 has the ability to vary between an opening configuration and a closing configuration. The assembly mold 20 comprises a first rigid mold part 22 delimiting a first imprint 220 having a shape complementary to the shape of the desired first layer 12 and a second rigid mold part 24 delimiting a second imprint 240 having a shape complementary to the shape of the desired second layer 14.

[0115] In one embodiment of step E1, the initial stack 28 is directly produced in the assembly mold 20. Alternatively, the initial stack 28 is at least partially produced outside the assembly mold 20 before being put in place and possibly finalized in the assembly mold 20. Thus, according to this embodiment, step E1 comprises a step of forming the initial stack 28 in which the following elements are superimposed: the at least one first dry reinforcement intended to belong to the first layer 12 and to enter into the composition of the first composite material, said plurality of photovoltaic cells 16, the at least one second dry reinforcement intended to belong to the second layer 14 and to enter into the composition of the second composite material.Furthermore, step E1 may comprise a rolling step, implemented between the step of forming the initial stack and the step of placing the initial stack 28 in the assembly mold, said rolling step comprising the rolling of the initial stack 28 to form a laminated initial stack 28 used as initial stack 28 for the following steps of the manufacturing method, step E1 of placing the initial stack 28 in the assembly mold then being implemented with the laminated initial stack 28. According to one embodiment, the rolling step further comprises the rolling of the initial stack 28 and the at least one encapsulation material 181, 182.

[0116] The implementation of step E1 can be automated using suitable handling robots, manually or semi-automatically. At the time of its implementation, the first and second dry reinforcements, for example made of glass, are not impregnated with a resin.

[0117] An example of such an assembly mold 20 is illustrated in FIG. 5, which is suitable for obtaining the photovoltaic module 10 of FIG. 4.

[0118] The assembly mold 20 can vary between the closing configuration (occupied in phases P1 to P3 in FIGS. 8 and 10) and the opening configuration illustrated in FIG. 5. The opening configuration can be adopted for the implementation of step E1, then allow removal of the photovoltaic module 10 from the assembly mold 20 after its manufacture or for the implementation of step E3 and / or step E4, these being described later.Depending on the design of the assembly mold 20, the transition from the closed configuration to the open configuration and vice versa can be done by a relative movement between the first mold part 22 and the second mold part 24, this relative movement being a combination between: a translation along a first axis of the reference frame associated with the photovoltaic module 10 to be manufactured and oriented along the direction in which the different layers and elements of the stack are stacked, and / or a pivoting around a second axis of this reference frame oriented transversely to the first axis.

[0119] The first mold part 22 and the second mold part 24 are such that, in the closed configuration of the assembly mold 20, the first mold part 22 and the second mold part 24 are spaced apart by a predetermined air gap 26 preferably greater than or equal to the thickness of the initial stack 28 and delimit between them a closed cavity 30 capable of receiving the initial stack 28. For example, said cavity 30 is sealed. The predetermined air gap 26 and the cavity 30 are shown diagrammatically in FIGS. 8 and 10. A first seal 222 of the first mold part 22 comes into contact with a second seal 242 of the second mold part 24 in order to ensure a seal such that, in the closed configuration, the cavity 30 can be placed in conditions first of depression then of overpressure during step E3, in comparison with the ambient pressure outside the assembly mold 20.It is possibly possible to have a depression in the cavity 30 without mechanical pressurization (this pressure being symbolized in the figures by the arrows marked F1) of the initial stack 28.

[0120] The establishment of the predetermined air gap 26 in the closing configuration may result from the mechanical abutment of a first stop secured to the first mold part 22 against a second stop secured to the second mold part 24, the mechanical abutment of these first and second stops being accompanied by the establishment of the seal described previously by means of the first and second seals 222, 242.

[0121] The difference between the value of the predetermined air gap 26 and the thickness of the initial stack 28, this difference being greater than or equal to zero and potentially adjustable, makes it possible in practice to influence the thickness of the first layer 12 formed in the first composite material and the thickness of the second layer 14 formed in the second composite material and the thickness and / or the internal pressure of the quantity of resin: which hermetically coats the photovoltaic cells 16 and assembles them to the first layer 12 and to the second layer 14. and / or which assembles the first layer 12 to the encapsulation material 181 and / or to the photovoltaic cells 16, and / or which assembles the second layer 14 to the encapsulation material 182 and / or to the photovoltaic cells 16.

[0122] Preferably, the assembly mold 20 comprises adjustment elements configured so as to adjust the value of the predetermined air gap 26, ultimately making it possible to vary the value of the thickness of the manufactured photovoltaic module 10.

[0123] According to one embodiment, these adjustment elements can be chosen from: elements making it possible to vary the position of the first stop relative to the rest of the first mold part 22, elements making it possible to vary the position of the second stop relative to the rest of the second mold part 24, shims of variable heights capable of being positioned between the first stop and the second stop in the closing configuration of the assembly mold 20.

[0124] In the embodiment providing the presence of an encapsulating assembly 18, the manufacturing method may optionally comprise a step consisting of pre-laminating the at least one encapsulating material 181, 182 present. This step may be carried out prior to the implementation of step E1 or may also be carried out directly in the assembly mold 20, before the implementation of step E2.

[0125] Still referring to Figure 3, the manufacturing method then comprises a resin transfer molding step E2, in which a resin in the liquid state is injected into the cavity 30 in such a way that the resin passes through the at least one first dry reinforcement as well as through the at least one second dry reinforcement. Advantageously, using a resin having a maximum viscosity of between 300 mPa.s and 400 mPa.s makes it possible to correctly inject the resin for the implementation of step E2.

[0126] According to an embodiment in which the cavity 30 is sealed, after vacuum conditions have been applied prior to the injection of the resin, this injection of the resin first involves a progressive and significant increase in the pressure in the cavity 30, involving an advantageous effect of compacting the various components of the photovoltaic module 10 during the injection of the resin. In step E2, it is understood that the molding is obtained by the transfer under pressure of the injected resin, this pressure being able for example to reach up to 50.10 5 Pa for the case of a thermosetting resin, such as an epoxy resin, or reach up to 20.10 5 Pa for the case of a thermoplastic resin, such as for example an acrylic resin, for example known under the commercial name "Elium". This compaction effect of several tens of bars (where 1 bar is equal to 10 5Pa) combined with high temperature conditions (in particular above 100°C or even ideally above 150°C and below 250°C) provide the opportunity for optimal resin injection pressure and temperature conditions to provide good mechanical strength of the photovoltaic module 10. These arrangements are obtained by advantageously overcoming the risks of creep that existed in existing solutions. Step E2 of resin transfer molding, this technique also being known by the acronym “RTM” for “Resin Transfer Molding” according to the appropriate English terminology, is carried out in the assembly mold 20 delimiting the cavity 30 then closed and possibly coupled to a heating press, making it possible to reach the pressure and temperature ranges necessary for injecting the resin into the stack during step E2 and then for its consolidation during step E3.Unlike techniques using pre-impregnated reinforcing fibers (yarns or fabrics already loaded with resin), the RTM technique uses dry reinforcements, i.e. the resin is added in the final phase of the process, once the reinforcement structure of the part is fully constructed.

[0127] It is also possible to implement step E2 while the cavity 30 is not sealed. In this case, the first and second seals 222, 242 comprise atmospheric vents 232 configured to allow air to pass through. Advantageously, such vents are arranged at ends of the cavity 30, so that the resin expels the air present in the cavity at the vents. Although this embodiment with an air-permeable cavity 30 gives satisfactory results, it is preferable to use a sealed cavity 30, which reduces the risk of trapping air bubbles in the encapsulating assembly 18.

[0128] The use of properly designed photovoltaic cell skeletons 16 can prevent their breakage during step E2 under significant mechanical stress (the pressure can reach approximately 50.10 b Pa during the epoxy resin transfer molding operation), and to ensure their resistance to the main aging tests of the IEC 61215 standard, in particular the mechanical load test at + / - 2400 Pa.

[0129] As can be seen in Figure 3, the manufacturing method then comprises a step E3 consisting of ensuring hardening of the resin previously injected in step E2. Step E3 is carried out by a suitable adjustment of the temperature prevailing in the cavity 30, depending on the nature of the resin injected in step E2. The combination of the at least one first dry reinforcement and the resin in the hardened state at the end of step E3 constitutes the first composite material. The combination of the at least one second dry reinforcement and the resin in the hardened state at the end of step E3 constitutes the second composite material.The resin can be hardened by polymerization in the case where the resin has thermoplastic characteristics (this requires a lowering of the temperature) or by crosslinking in the case where the resin has thermosetting characteristics (this requires maintaining or increasing the temperature for a certain period of time to cause crosslinking).

[0130] In the particular embodiment where the initial stack 28 comprises at least one encapsulation material 181, 182, it may be provided that during step E2, the temperature of the resin is adapted as a function of the at least one encapsulation material 181, 182 so that the at least one encapsulation material 181, 182 undergoes at least partial melting under the effect of calories transmitted by the resin and converts the at least one encapsulation material 181, 182 into the encapsulating assembly 18 already described, allowing the latter to adhere on the one hand to the plurality of photovoltaic cells 16 and on the other hand to the first layer 12 via the layer of encapsulation material 181 and / or to the second layer 14 via the layer of encapsulation material 182.

[0131] It is therefore possible to implement 10-plane or lopsided photovoltaic modules, based on photovoltaic cells 16, for example made of crystalline silicon, with or without an encapsulating assembly 18, with the first composite material and the second composite material respectively on the first front face 12 and on the second rear face 14 of the photovoltaic module 10, by the resin transfer molding step E2. The first composite material and the second composite material used are implemented directly during the process from the at least one first dry reinforcement to be integrated into the first composite material and the at least one second dry reinforcement to be integrated into the second composite material, by using the single resin thus injected and then hardened.The manufacturing method allows its implementation in a temperature-pressure range making it possible to obtain the optimal mechanical properties of the first and second composite materials respectively on the first front face 12 and on the second rear face 14 of the photovoltaic module 10. As will be specified later, the resin injected in step E2 can be a thermosetting matrix or a thermoplastic matrix.

[0132] Preferably, the at least one encapsulation material 181, 182 has a thickness of between 100 μm and 2000 μm and is chosen from: a thermoplastic elastomer itself chosen from: polyolefin, thermoplastic polyurethane (TPU), polyvinyl butyral (PVB), functional polyolefin, ionomer; a thermosetting elastomer itself chosen from: polyethylene-vinyl acetate (EVA), a crosslinked silicone, a crosslinked polyolefin (POE), a crosslinked polyurethane (PUR).

[0133] The above selection of the encapsulation material 181, 182 is carried out to avoid or limit creep phenomena which may occur due to the high pressure (several tens of bars) or contact with the mold parts 22, 24, as well as turbulence phenomena due to interaction between the resin and the encapsulation material(s) 181, 182 which could be induced by the softening of an encapsulation material 181, 182 which is poorly selected.

[0134] It is therefore well understood that at the end of step E1, the resin necessary for obtaining and hardening is absent. After the placement of this dry stack in the assembly mold 20, it is in step E2 that the same and unique resin is injected under pressure and hot, jointly: into the volume which will constitute the first layer 12, into the volume which will constitute the second layer 14, and into any volume potentially present spatially around the photovoltaic cells 16, in direct contact with them or around the at least one encapsulation material 181, 182.

[0135] In the case where no encapsulating assembly 18 is provided, then the resin fills during step E2 (before the hardening of step E3) the entire volume present spatially around the photovoltaic cells 16. The resin then fulfills after step E3: a first function consisting of hermetically coating the photovoltaic cells 16 as a substitute for the encapsulating assembly 18, a second function which consists of ensuring the consolidation of the first and second layers 12, 14 by naturally entering into the composition respectively of the first composite material and of the second composite material in combination with the at least one first dry reinforcement and the at least one second dry reinforcement, respectively, a third function consisting of adhering the different layers of the stack of the photovoltaic module 10 to each other.

[0136] Very advantageously, these different functions are obtained in a very simple, rapid, efficient, economical, easily automatable and potentially with a good production rate, by the implementation of a single E2 resin transfer molding step where it is sufficient to inject the resin under pressure and hot in a suitable manner.

[0137] In the case of the use of a thermoplastic resin and where in particular it is possible to advantageously dispense with the encapsulating assembly 18, the recyclable nature is facilitated compared to the variant where the encapsulating assembly 18 is present, because there is then only one type of resin (polymer) present in the photovoltaic module 10.

[0138] In the case where the encapsulating assembly 18 is provided, then the resin fills and fills before hardening: all the volume present spatially between the at least one first dry reinforcement and the possible encapsulating material 181 arranged on the side of the at least one first dry reinforcement, all the volume which corresponds to the first layer 12, all the volume present spatially between the at least one second dry reinforcement and the possible encapsulating material 182 arranged on the side of the at least one second dry reinforcement, all the volume which corresponds to the second layer 14,

[0139] In the case where the encapsulating assembly 18 is provided, the resin then fulfills, after step E3: a first function consisting of securing the encapsulating assembly 18 and / or the photovoltaic cells 16 with the first layer 12 on the one hand and with the second layer 14 on the other hand, finally ensuring the cohesion of the different parts of the photovoltaic module 10 between them to form a single-piece object, a second function which consists of ensuring the consolidation of the first and second layers 12, 14 by naturally entering into the composition respectively of the first composite material and of the second composite material in combination with the at least one first dry reinforcement and the at least one second dry reinforcement, respectively.

[0140] In the above and whether or not the encapsulating assembly 18 is present, an advantage is that all these functions are obtained by the resin itself, by means of a single operation consisting of the molding by transfer of resin under pressure and hot obtained by simple adapted injection of the resin, then its cooling. This allows the manufacturing process to have a very small number of steps, which obviously favors simplicity, speed, limitation of costs, a possibility of easy automation and interesting rates. It is possible to possibly do without the encapsulation materials 181, 182, which reinforces the aforementioned advantages, as well as a limitation of the size and the surface mass, without affecting the mechanical strength of the manufactured photovoltaic module 10. Finally, a photovoltaic module 10 designed in this way can be more easily dismantled at the end of its life.

[0141] The adhesion of the different components and layers within the photovoltaic module 10, to make it a single-piece object, is obtained essentially by the presence of the resin injected following step E2 and, in the case where the encapsulating assembly 18 is provided, under the additional and advantageous effect of the heat input to the at least one encapsulation material 181, 182 (with a view to achieving its at least partial melting) caused by the injection and circulation of the resin under pressure and at high temperature induced by the implementation of step E2.In other words, in the case of the presence of the encapsulating assembly 18, the heated and injected resin allows not only the desired joint consolidation of the first layer 12 and the second layer 14 (by polymerization in the case where the resin is thermoplastic or by crosslinking in the case where the resin is thermosetting) but also the assembly of the first layer 12 and the second layer 14 to the photovoltaic cells 16 and / or to the encapsulating assembly 18, by means of a single and same resin, or even optionally in addition a hermetic coating of the photovoltaic cells 16 as a substitute for the encapsulating assembly 18.

[0142] Thus, the resin injected by step E2, identical for the first and second layers 12, 14, is used to assemble the stack and at the same time to actually manufacture the first front layer 12 and the second rear layer 14; all these actions are carried out globally in a single operation covering steps E2 to E4.

[0143] All these advantages can also be obtained for lightweight photovoltaic modules (in particular compatible with a wide range of mass per unit area ranging from a few kg / m 2 up to several tens of kg / m 2), adapted to meet severe mechanical strength requirements (in particular according to mechanical strength conforming to conventional administrative standards in the field, typically standards IEC 61215 and IEC 61730), possibly of a left shape, while avoiding any risk of creep and / or blistering of the encapsulation materials 181, 182, which guarantees high repeatability of the manufacturing process and excellent reliability of the photovoltaic modules 10 manufactured. To enter into the composition of the first composite material following steps E3 and E4, it is possible for the at least one first dry reinforcement to be associated with at least one other dry reinforcement having or not another nature in terms of composition, shape, arrangement, orientation, thickness etc.Symmetrically, to enter into the composition of the second composite material following steps E2 and E3, it is possible for the at least one second dry reinforcement to be associated with at least one other dry reinforcement having or not another nature in terms of composition, shape, arrangement, orientation, thickness etc.

[0144] The success of the manufacturing process may depend on the choice of the photovoltaic cells 16 and their connectors, in order to guarantee resistance to the very high level of pressure which is applied in step E3, as well as the calibration of the predetermined air gap 26 of the assembly mold 20 to avoid the displacement and breakage of the cells 16 in contact with the mold parts 22, 24 while minimizing the creep of any encapsulation materials 181, 182 towards low points of the mold resulting from the heating conditions, which would inevitably lead to obtaining a photovoltaic module having a non-uniform thickness.

[0145] The manufacturing process also has the advantage of being able to be implemented with a thermosetting resin or with a thermoplastic resin.

[0146] Furthermore, the use of the assembly mold 20 having the two mold parts 22, 24 made of an advantageously rigid material and configured to adopt the predetermined air gap 26 makes it possible to guarantee the presence of an air gap having a perfectly repeatable value and independent of the mechanical pressure F1 applied by the assembly mold 20 on the photovoltaic module 10 and independently of the pressure of the gas present in the cavity 30. These arrangements guarantee excellent repeatability of step E2 and good reliability of the manufactured photovoltaic modules 10. The use of an assembly mold 20 in accordance with steps E2 and E3 also makes it possible to address the problems of risk of creep of the possible encapsulation materials 181, 182 towards low points of the mold.

[0147] The manufacturing method which has just been described advantageously makes it possible to produce complex, shaped parts with awkward shapes, with curvatures of the photovoltaic module 10 within the limit of the mechanical strength of the photovoltaic cells 16, but also a possibility of adding inserts or grooved edges or those with complex shapes (stiffeners, etc.).

[0148] The manufacturing method makes it possible to dispense with the use of front and rear faces made of glass and / or non-reinforced polymer, and to replace this respectively with a first composite material and with a second composite material obtained by step E2 of resin transfer molding using, in a single operation by means of hot injection and under pressure, a single and same resin for the first and second layers 12, 14. The manufactured photovoltaic module 10 may have a surface mass for example between 1 kg / m 2 and 8 kg / m 2, or more particularly between 4 kg / m 2 and 6 kg / m 2 , which is significantly lower than that of a classic glass module which is typically between 10 and 12 kg / m 2 .

[0149] In the variant where the first layer 12 to be obtained has a left shape and where the second layer 14 to be obtained also has a left shape, the first imprint 220 has a first shape such that the first layer 12 is shaped according to a first left shape at the end of step E3 and the second imprint 240 has a second shape such that the second layer 14 is spatially shaped according to a second left shape at the end of step E3.

[0150] According to a particular embodiment, step E2 comprises, after step E1, the following steps: a step E21 of depression applied to the cavity 30 delimited by the assembly mold 20 in the closed configuration, relative to the pressure prevailing outside the cavity 30, optionally, a step E32 of heating the initial stack 28, a step E22 of injecting the resin into the cavity 30 in a pressurized manner at a pressure strictly higher than the pressure prevailing in the cavity 30.

[0151] According to a particular embodiment, it is possible for the assembly mold 20 to be heated during step E2, for example at a constant temperature with an oil thermoregulator. In this case, step E2 comprises step E32 of heating the initial stack 28 by transmitting calories from the assembly mold 20 to the initial stack 28. It is also possible for such a heating step E32 to follow the injection of the resin during step E22. In this case, the injected resin transmits calories to the initial stack 28 to implement the heating step E32.

[0152] Thus, these are not necessarily successive steps. Step E32 can thus be implemented before, during or after step E1. Step E22 is carried out after step E21.

[0153] According to a particular embodiment, in step E21, the pressure established in the cavity 30 is between 0.5.10 5 Pa and 1.105 Pa.

[0154] According to one embodiment, step E32 consists of heating the first mold part 22 and / or the second mold part 24.

[0155] For example, for the implementation of step E32 the first mold part 22 and the second mold part 24 can be mechanically and thermally coupled to a heating press, configured to be able to move the mold parts 22, 24 relative to each other in order to be able to apply the mechanical pressure F1, and to be able to transmit calories from the heating press to the mold parts 22, 24 by thermal conduction or by integration of heating resistors. In general, it is not necessarily necessary to provide a heating press, in the sense that the heating means can be either internal or external to the tools of the assembly mold 20.

[0156] Furthermore, as shown diagrammatically in Figure 3, step E2 may optionally comprise a step E20 which consists of heating the resin prior to the implementation of step E22. In particular, step E20 may be carried out in a manner to reach after step E20 (before injection) a temperature guaranteeing that the temperature of the resin is, at the time of contact between the resin and the at least one encapsulation material 181, 182, strictly higher than a temperature at which the at least one encapsulation material 181, 182 undergoes at least partial melting.

[0157] In the case where the resin is thermoplastic, the temperature necessary for implementing step E2 may be close to room temperature, below 100°C or alternatively above 100°C, or even above 150°C and below 250°C, depending on the type of resin used. In the case where the resin is thermosetting, the temperature necessary for implementing step E3 is typically between 60°C and 130°C.

[0158] In parallel with this, the temperature at which the at least one encapsulation material 181, 182 undergoes at least partial melting is generally between 60 and 180°C, preferably between 80°C and 150°C, this temperature allowing the integration of the photovoltaic cells 16 in the encapsulating assembly 18. The temperature of this implementation must be carefully adjusted to avoid as much as possible the creep of the encapsulating assembly 18, favored by the possible lopsided shape of the photovoltaic module 10. Similarly, the air gap 26 of the assembly mold 20 must be adjusted precisely so as not to damage the photovoltaic cells 16.

[0159] In a first possible implementation, step E20 is carried out so that the resin reaches a temperature, before its injection in step E22, which is already higher than the temperature at which the at least one encapsulation material 181, 182 undergoes at least partial melting. Alternatively, in a second possible implementation, step E20 is carried out so that the resin reaches, before its injection in step E22, a temperature (for example of the order of 50°C, corresponding to a sort of preheating) which is strictly lower than the temperature at which the at least one encapsulation material 181, 182 undergoes at least partial melting.In this second possibility, it is the fact of circulating in the cavity 30 of the assembly mold 20 having been previously heated, which makes it possible to increase the temperature of the resin after its injection until it becomes higher than the temperature at which the at least one encapsulation material 181, 182 undergoes at least partial melting.

[0160] Advantageously, it is provided that the temperature reached by the initial stack 28 in step E32 is maintained during all or part of step E22. This promotes the implementation of resin transfer molding in a spatially homogeneous manner throughout the cavity 30, and homogeneously over time by avoiding variations in behavior of the resin which would otherwise be induced by a drop in temperature within the stack if the temperature were not maintained during step E22.

[0161] According to a particular embodiment, during step E22, the injection of the resin is carried out in a directed manner in a preferential direction in which the resin preferentially circulates inside the cavity 30 delimited by the assembly mold 20. For example, it is appropriate to refer to the arrows F6 in FIGS. 6, 8 and 10.

[0162] Referring now more particularly to Figure 6 which is a sectional view of the assembly mold 20, it can be observed that the assembly mold 20 comprises at least one discharge outlet 36 in fluid connection with a suction system (not shown) making it possible to establish a vacuum in the cavity 30 delimited by the assembly mold 20 and / or at least one supply inlet 32 ​​in fluid connection with a supply system making it possible to inject the resin towards the cavity 30 delimited by the assembly mold 20.

[0163] According to the variant illustrated in Figure 6, at the end of step E1, the at least one supply inlet 32 ​​and the at least one discharge outlet 36 are located on either side of the initial stack 28 in a first direction D1. This first direction D1 is oriented in the preferential direction in which the resin preferentially circulates inside the cavity 30 delimited by the assembly mold 20.

[0164] Still with reference to Figure 6, the assembly mold 20 may preferably comprise at least one first draining medium 34 into which the at least one feed inlet 32 ​​opens and / or at least one second draining medium 38 into which the at least one discharge outlet 36 opens, each of the first draining medium 34 and the second draining media 38 ensuring drainage of the resin along a second direction D2 oriented transversely (for example substantially orthogonal to within 10°) to the first direction D1.

[0165] The circulation within the first draining medium 34 of the resin injected by the at least one supply inlet 32 ​​is symbolized in Figure 6 by the arrows F5. The circulation within the second draining medium 38 of the resin which will be sucked up by the at least one discharge outlet 36 is symbolized in Figure 6 by the arrows F7.

[0166] The phenomenon of depression at the level of the at least one discharge outlet 36 is shown diagrammatically by the arrow F4 in Figures 8 and 10, in phases P1 and P2. The phenomenon of injection of the resin at the level of the at least one supply inlet 32 ​​is shown diagrammatically by the arrow F3 in Figures 8 and 10, in phase P2.

[0167] By these provisions, it is ensured that the resin can pass, during the implementation of step E2: through the at least one first dry reinforcement along the entire length of the photovoltaic module 10 counted along the first direction D1 and along the entire width of the photovoltaic module 10 counted along the second direction D2, and this over at least the entire thickness sought for the first layer 12, and through the at least one second dry reinforcement along the entire length of the photovoltaic module 10 counted along the first direction D1 and along the entire width of the photovoltaic module 10 counted along the second direction D2, and this over at least the entire thickness sought for the second layer 14.

[0168] Alternatively and according to an embodiment illustrated for example in Figure 5, in which the first and second seals 222, 242 comprise atmospheric vents 232, during step E2, said atmospheric vents 232 are configured to allow air to pass. In this case, the assembly mold 20 comprises at least one supply inlet 32 ​​in fluid connection with a supply system, the evacuation function being guaranteed by the atmospheric vents 232. A suction system is then not necessary.

[0169] According to a particular embodiment, in step E22, the injection of the resin is controlled (in terms of flow rate, outlet pressure, etc.) so that the pressure prevailing in the cavity 30 delimited by the assembly mold 20 is between 2.10 5 Pa and 50.10 5Pa. As already indicated, this very high pressure value, while avoiding the known risks of creep of the encapsulation materials in existing solutions, offers the opportunity for optimal resin injection pressure and temperature conditions for the mechanical strength of the photovoltaic module 10.

[0170] It is possible to consider using in step E2 any resin capable of being hot injected and compatible with a resin transfer molding technique, having good adhesion to the encapsulating material 181, 182 or the photovoltaic cells 16. For the first face 12 of the front side, the resin will preferably have a refractive index close to that of the glass used for the composition of the at least one first dry reinforcement used (which is of the order of 1.51) to provide good transparency.

[0171] The first mold part 22 and the second mold part 24 of the assembly mold 20 exert, on the stack, mechanical pressure during all or part of step E2, in particular during all of steps E21, E32 (phase P1) and E22 (phase P2), and during all or part of step E3 (phase P3). These arrangements are illustrated for example in Figures 8 and 10.

[0172] This mechanical pressure, identified by the arrows F1 in Figures 8 and 10 during the phases P1 to P3, can be obtained by the fact that the assembly mold 20 is associated with a press capable of exerting this mechanical pressure F1, for example a heating press adapted in addition to the temperature setting necessary for the implementation of step E32. For example, the first mold part 22 and the second mold part 24 can be mechanically (and thermally) coupled to a (heating) press configured to be able to move the mold parts 22, 24 relative to each other in order to be able to apply the mechanical pressure F1.

[0173] According to one embodiment, the mechanical pressure F1 is between 90.10 5 Pa and 150.10 5 Pa, and more particularly equal to 90.10 5 Pa, or equal to 150.10 5 Pa.

[0174] Finally, as can be seen in Figure 3, the manufacturing method comprises a step E4 consisting of opening the assembly mold 20, so that the latter passes from the closed configuration to the open configuration. Step E4 is implemented after step E3. These arrangements correspond to phases P4 in Figures 7 to 10. This step E4 of opening the assembly mold 20 can be implemented in different ways, in particular depending on the type of resin used.

[0175] According to a first embodiment, the resin is a thermoplastic resin. This advantageously makes it possible to confer a fundamental characteristic on the photovoltaic module 10: to be a recyclable material at the end of its life. Furthermore, once the photovoltaic module 10 has been manufactured, it is possibly possible to make the resin flexible or liquid again by providing a new supply of calories to the resin that is sufficient to change the state of the resin, making it possible, for example, to make the photovoltaic module 10 more easily removable than in the case of a thermosetting resin.

[0176] For example, the thermoplastic resin used for the first layer 12 may be chosen from: styrene-acrylonitrile (SAN), polycarbonate (PC), polystyrene (PS), poly(methyl methacrylate) (PMMA), polyamide (PA), polyvinylidene fluoride (PVDF), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ETCFE), polyvinyl fluoride (PVF), polytetrafluoroethylene (PTFE), or equivalents.

[0177] The thermoplastic resin used for the second layer 14 can be chosen from those described above concerning the first layer 12, or from: polyethylene (PE), polypropylene (PP), polyethylene terephthalate (PET), polyvinyl chloride (PVC), acrylonitrile-butadiene-styrene (ABS).

[0178] It is therefore well understood that the thermoplastic resin used during step E2 can be the same for the first composite material forming the first layer 12, and for the second composite material forming the second layer 14.

[0179] Still in this first embodiment where the resin is a thermoplastic resin, the temperature to be reached within the initial stack 28 during step E32 is between 15°C and 260°C.

[0180] Still during the first embodiment where the resin is a thermoplastic resin, step E3 comprises a step of lowering the temperature of the stack resulting from step E2 compared to the conditions present during step E2. These arrangements are visible in Figures 7 and 8.

[0181] According to a first variant, step E3 is implemented by opening the assembly mold 20 leading to cooling of the stack resulting from step E32 by natural convection. This first variant is more suitable for thermosetting resins which have the advantage of not undergoing or only slightly undergoing shrinkage during cooling.

[0182] According to a second variant, step E3 comprises a cooling step implemented in a cooling mold separate from the assembly mold 20. It is thus possible to limit shrinkage phenomena. Such a variant is suitable both for the cooling of thermosetting resins, but also for thermoplastic resins.

[0183] In support of the embodiment where the resin injected in step E2 is a thermoplastic resin, FIG. 7 represents a first curve illustrating an example of evolution, with different successive phases P1 to P4, of the temperature adopted by the assembly mold 20 as a function of time in the manufacturing process using a thermoplastic resin, while FIG. 8 schematically represents the behavior of the assembly mold 20 and of the stack during a first initial phase PO then during the different phases P1 to P4 corresponding to those defined in FIG. 7.

[0184] Figures 7 and 8 refer to different successive situations of an example of a manufacturing process implementing the general lessons presented above, with five successive phases PO to P4.

[0185] These successive phases PO to P4 are notably applied for the purpose of manufacturing a photovoltaic module 10 having a planar shape without this being limiting, and comprising (these elements are not illustrated in detail in FIGS. 7 and 8): a first layer 12 having a planar shape, formed in the first composite material, transparent and intended to form the front face of the photovoltaic module 10, which is intended to receive a luminous flux, a second layer 14 having a planar shape, formed in a second composite material, and intended to form a rear face of the photovoltaic module 10, a plurality of photovoltaic cells 16 arranged side by side, electrically connected to each other and located between the first layer 12 and the second layer 14, an encapsulating assembly 18 ensuring encapsulation of all or part of the photovoltaic cells 16.

[0186] The presence of the encapsulating assembly 18 is however optional, as already indicated.In a first phase PO, the initial stack 28 is formed where the initial stack 28 successively comprises the following superimposed elements, going from the front face to the rear face of the photovoltaic module 10: at least one first dry reinforcement (for example three in number) intended to belong to the first layer 12 and to enter into the composition of the first composite material, a first encapsulation material 181 arranged between the first dry reinforcement and the photovoltaic cells 16, the plurality of photovoltaic cells 16, where these photovoltaic cells are already interconnected with each other, a second encapsulation material 182 arranged between the second dry reinforcement and the photovoltaic cells 16, at least one second dry reinforcement (for example three in number) intended to belong to the second layer 14 and to enter into the composition of the second composite material.

[0187] This operation can be carried out manually or by means of handling robots or semi-automatically. Within the initial stack 28, the plurality of photovoltaic cells 16 is located between the at least one first dry reinforcement and the at least one second dry reinforcement, and each of the encapsulation materials 181, 182 is located between the at least one first dry reinforcement and the at least one second dry reinforcement as well.

[0188] The notion of “first” and “second” encapsulation materials 181, 182 is only intended to distinguish them from the point of view of their different positioning within the initial stack 28. These two encapsulation materials 181, 182, although positioned at different locations, may possibly be of the same nature both in composition and thickness or number of layers. Moreover, it is possible for the two encapsulation materials 181, 182 to be formed either in two different and independent plies, or in a single ply forming a unitary assembly.

[0189] Then in a second phase P1, what corresponds to step E1 of placing the initial stack 28 in the assembly mold 20 is carried out first, initially adopting the opening configuration to be able to access the interior of the cavity 30 and place the initial stack 28 there. This operation can be carried out manually or by means of handling robots or semi-automatically.

[0190] Then, still in the second phase P1, the assembly mold 20 is passed from the opening configuration to the closing configuration, the first mold part 22 and the second mold part 24 then being separated by the predetermined air gap 26 which is strictly greater than the thickness of the initial stack 28. The closed cavity 30 seals the initial stack 28.

[0191] Still during the second phase P1, step E32 of heating the assembly mold 20 and step E21 of applying depression to the cavity 30 from the pressure prevailing outside the cavity 30 are carried out, these steps being able to be implemented in any order and possibly with a time overlap between them.

[0192] This first results in an increase in the temperature of the initial stack 28. This is the reason why, in phase P1, the curve illustrated in FIG. 7 (which represents the evolution of the temperature (on the ordinate) of the initial stack 28 as a function of time (on the abscissa)) is presented in the form of a profile increasing over time, for example in a rectilinear manner. As an example to carry out this heating according to step E32, the assembly mold 20 is placed at a constant temperature, for example 100°C, involving an increase in the temperature of the initial stack 28. In any case, it is provided that the nominal temperature is strictly higher than the functional temperature at which the at least one encapsulation material 181, 182 undergoes at least partial melting (the functional temperature generally being between 70 and 180°C, preferably between 80°C and 150°C).

[0193] The heat input to the initial stack 28 due to the heating phenomenon of the assembly mold 20 is shown diagrammatically by the arrows F0.

[0194] Alternatively, the initial stack 28 could have been produced simultaneously with the heating of the assembly mold 20, allowing a saving of time, the initial stack 28 then being deposited in the already hot assembly mold 20.

[0195] It is recalled that it is not necessarily necessary to provide a heating press, in the sense that the heating means can be either internal or external to the tools of the assembly mold 20.

[0196] In the second phase P1, the implementation of step E21 may consist of establishing a vacuum at the at least one discharge outlet 36 by operating the suction system (which may be equipped with a pump, a filter and be configured to be able to suck both the gases present in the cavity 30 and the resin previously injected into the cavity). During step E21, the resin is not injected through the at least one supply inlet 32. The arrow F4 symbolizes the extraction of the gases by the vacuum effect and this therefore results in the establishment of pressure conditions close to vacuum within the cavity 30 at the end of step E21. This will allow the implementation of the subsequent resin transfer molding step E2. Still in the second phase P1, the assembly mold 20 exerts the mechanical pressure (for example of approximately 5.10 5Pa), shown diagrammatically by the arrows F1, which implies a compression of the stack present in the cavity 30 of the assembly mold 20.

[0197] Then a third phase P2 begins, which corresponds concretely to the implementation of step E22 of injecting the resin into the cavity 30 in a pressurized manner at a pressure strictly higher than the pressure prevailing in the cavity 30.

[0198] The implementation of the resin injection step E22 may consist of establishing a vacuum at the at least one discharge outlet 36 by operating the suction system and / or establishing an overpressure at the at least one supply inlet 32 ​​by operating the supply system. During the step E22, the resin is injected through the at least one supply inlet 32, which is symbolized by the arrow denoted F3 in the phase P2 of FIG. 8, while at the same time the extraction of the gases by the vacuum effect at the at least one discharge outlet 36 is prolonged, which is symbolized by the arrow F4 in the phase P2 of FIG. 8.

[0199] This then results in an increase in pressure within the cavity 30 and within the stack present in the cavity 30, during resin transfer molding. This requires high-pressure compaction of the different layers and components of the photovoltaic module 10, which is important for the high mechanical properties obtained.

[0200] Prior to injection, the resin undergoes heating in accordance with step E20, making it possible: either to guarantee that the resin has, from the time of its injection, a temperature higher than the functional temperature beyond which each encapsulation material 181, 182 undergoes at least partial melting under the effect of calories transmitted by the resin, or to guarantee that the resin has, at the time of its injection, a temperature strictly lower than the functional temperature but likely to increase (under the effect of the calories transmitted to the resin by the assembly mold 20 during step E2; arrows F1) during the circulation of the resin within the cavity 30 in a manner sufficient to become strictly higher than the functional temperature.

[0201] The circulation in the second direction D2 within the first draining medium 34 of the resin previously injected at the level of the at least one supply inlet 32 ​​is symbolized in FIG. 6 by the arrows F5. The circulation directed in the first direction D1, in a direction going from the first draining medium 34 to the second draining medium 38, in particular within the stack being impregnated by the circulating resin, is symbolized by the arrows F6 both in FIG. 8 and in FIG. 6. The circulation in the second direction D2, within the second draining medium 38, of the resin which will be sucked in by the at least one discharge outlet 36 is symbolized in FIG. 6 by the arrows F7.By these arrangements, it is ensured that the resin, hot and under pressure, passes in a spatially homogeneous manner: through the at least one first dry reinforcement along the entire length of the photovoltaic module 10 counted along the first direction D1 and along the entire width of the photovoltaic module 10 counted along the second direction D2, and this over at least the entire thickness sought for the first layer 12, and through the at least one second dry reinforcement along the entire length of the photovoltaic module 10 counted along the first direction D1 and along the entire width of the photovoltaic module 10 counted along the second direction D2, and this over at least the entire thickness sought for the second layer 14.

[0202] The temperature reached by the initial stack 28 in step E32 (at the end of the second phase P1) is maintained during all or part of step E22, preferably until the end of step E22, therefore until the end of the third phase P2. This is the reason why, in the third phase P2, the curve illustrated in FIG. 7 is in the form of a constant profile over time. This promotes the implementation of resin transfer molding in a spatially homogeneous manner throughout the cavity 30, and homogeneously over time by avoiding variations in the behavior of the resin which would otherwise be induced by a drop in temperature within the stack if the temperature were not maintained during step E22.Throughout the third phase P2, the assembly mold 20 is maintained at the nominal temperature and continues to heat the stack and the injected resin, hence the presence of the arrows F0 in the third phase P2 in Figure 8.

[0203] Under the high pressure and temperature conditions, the resin in the liquid state fills and fills the following volumes during the third phase P2: the entire volume present spatially between the at least one first dry reinforcement and the encapsulation material 181 arranged on the side of the at least one first dry reinforcement, the entire volume which corresponds to the first layer 12, the entire volume present spatially between the at least one second dry reinforcement and the encapsulation material 182 arranged on the side of the at least one second dry reinforcement, the entire volume which corresponds to the second layer 14.

[0204] In this third phase P2, because the temperature of the resin being transferred for RTM molding is higher than the functional temperature from which the encapsulation materials 181, 182 undergo at least partial melting, the two encapsulation materials 181, 182 undergo melting under the effect of the calories transmitted by the resin, making it possible to convert the encapsulation materials 181, 182 into an encapsulating assembly 18 adhering on the one hand to the plurality of photovoltaic cells 16 and on the other hand to the first layer 12 and / or to the second layer 14. The organization of the encapsulation materials 181, 182 and the manner of ensuring their melting are adapted so that the encapsulating assembly 18 which results from this at least partial melting ensures encapsulation of all or part of the photovoltaic cells 16.It is in particular possible to obtain an encapsulating assembly 18 which encompasses all the photovoltaic cells 16 in a hermetic and waterproof manner.

[0205] In the manufacturing method described here, it is important to understand that a single resin is used in the composition of the two composite materials in which respectively the first layer 12 and the second layer 14 are formed, and that this resin, injected in the resin transfer molding step E2, fulfills not only the function of consolidating these two composite materials (in combination with the at least one first dry reinforcement to finalize the first layer 12 and in combination with the at least one second dry reinforcement to finalize the second layer 14) but also the function of ensuring by itself the adhesion of the different layers of the stack of the photovoltaic module 10 to each other, typically by the fact that it is this resin heated in a sufficient manner which ensures, at the time of step E2, the at least partial melting of the at least one encapsulation material 181, 182.

[0206] Then, in a fourth phase P3, what corresponds to step E4 of curing the previously injected resin is carried out. In the case of thermoplastic resin, this curing is carried out by polymerization. This is the reason why the temperature of the assembly mold 20 and of the stack is generally reduced, and this is the reason why, in phase P3, the curve illustrated in FIG. 7 is in the form of a profile decreasing over time, for example in a rectilinear manner. For example, the temperature of the assembly mold 20 decreases at a rate of 8°C / min, until it reaches the initial temperature at the start of phase PO. The heat transfer from the photovoltaic module 10 to the assembly mold 20 is shown diagrammatically by the arrows F2. Furthermore, throughout the fourth phase P3, the mechanical pressure (arrow F1) continues to be exerted by the assembly mold 20.The mechanical pressure applied while the two mold parts 22, 24 of the assembly mold 20 undergo the temperature decrease can be equal to the mechanical pressure F1 exerted during the phases P1 and P2 described previously (this is the reason why in phase P3 in Figure 8 the mechanical pressure is shown diagrammatically by the same arrows F1 as during phases P1 and P2), but it could be different depending on the needs.

[0207] Keeping the assembly mold 20 in the closed configuration and continuing to apply the mechanical pressure F1 during the resin curing step E3 makes it possible to best preserve the shape of the photovoltaic module 10 and to limit the risks of undesirable deformations under the effect of cooling and curing. Finally, with reference to FIG. 8, the fifth phase P4 can then begin, corresponding to the implementation of step E4 of opening the assembly mold 20, in which the assembly mold 20 passes from the closed configuration to the open configuration. Step E4 is implemented after step E3. During the fifth phase P4, the two mold parts 22, 24 undergo a relative separation by translation and / or rotation, until they are separated from each other by a distance strictly greater than the value of the predetermined air gap 26.In this relative separation of the mold parts 22, 24, the assembly mold 20 releases the mechanical pressure F1 previously exerted and the photovoltaic module 10 remains in the shape previously obtained, with a potential elastic return phenomenon.

[0208] According to a second particular embodiment, the resin is a thermosetting resin. For example, the transparent thermosetting resin used for the first layer 12 is an epoxy resin, a polyurethane resin (PUR), or a silicone. In the case of the second layer 14, the resin used may be chosen from transparent resins (epoxy resin, PUR resin, or a silicone). It is therefore well understood that the thermosetting resin used during step E2 may be the same for the first composite material forming the first layer 12, and for the second composite material forming the second layer 14. An advantage of using a thermosetting resin is, for many applications, to confer excellent mechanical strength to the manufactured photovoltaic module 10.

[0209] Still in this second embodiment where the resin is a thermosetting resin, the temperature to be reached within the initial stack 28 during step E32 is between 90°C and 130°C.

[0210] Still in this second embodiment where the resin is a thermosetting resin, step E3 comprises a step of maintaining or increasing the temperature of the stack resulting from step E2 relative to the conditions present during step E2. These arrangements are visible in Figures 9 and 10. According to one embodiment, the maintaining step is implemented for a duration greater than 1 min and less than 1 h, said duration being dependent on the resin used.

[0211] In support of this second embodiment where the resin is a thermosetting resin, Figure 9 represents a second curve illustrating an example of evolution, with different successive phases P1 to P4, of the temperature adopted by the assembly mold 20 as a function of time in the manufacturing process using a thermosetting resin, while Figure 10 schematically represents the behavior of the assembly mold 20 and of the stack during a first initial phase PO then during the different phases P1 to P4 corresponding to those defined in Figure 9. Figures 9 and 10 refer to different successive situations of an example of a manufacturing process implementing the general teachings presented above, with five successive phases PO to P4, in the particular case where the resin is thermosetting.

[0212] The principles of the different phases PO to P4 of the present example using a thermosetting resin are generally similar to the principles of the phases PO to P4 already described in the example using a thermoplastic resin, with certain technical differences induced precisely by the replacement of the thermoplastic resin by a thermosetting resin. Thus, all these principles will not be described again here to avoid unnecessary length of the text, focusing only on setting out these technical differences.

[0213] In the same way as for the method described in connection with figures 7 and 8, a thermosetting matrix can be used to manufacture a photovoltaic module 10 of planar shape or of lopsided shape, and integrating or not the at least one encapsulation material 181, 182.

[0214] The first phase PO of the process of figures 9 and 10 is carried out in an identical manner to that described in connection with figures 7 and 8.

[0215] Then in the second phase P1 of the method of figures 9 and 10, steps E1, E21 and E32 are implemented, as previously.

[0216] On the other hand, unlike the provisions previously described in the case of the use of a thermoplastic resin, the nominal temperature reached by the initial stack 28 at the end of step E32 may be between 90°C and 130°C in the case where the resin subsequently used is of the thermosetting type. In all cases and as previously, care is taken to ensure that the nominal temperature is greater than or equal to the functional temperature at which the at least one encapsulation material 181, 182 undergoes at least partial melting.

[0217] Then the third phase P2 is implemented, using the principles already described for phase P2 in connection with figures 7 and 8, except with regard to the value of the temperature of the resin during step E22. In the case of a thermosetting resin, the temperature at which the resin is used in order to carry out the resin transfer molding during step E22 is potentially lower than in the case of a thermoplastic resin.

[0218] Then, in the fourth phase P3 of figures 9 and 10, what corresponds to step E3 of curing the previously injected resin is carried out. In the case of a thermosetting resin, this curing is carried out not by polymerization, but by crosslinking. This is the reason why the temperature of the assembly mold 20 is maintained or increased during the fourth phase P3, and this is the reason why, in phase P3, the curve illustrated in figure 9 is in the form of a constant profile over time in a rectilinear manner (although this profile could be slightly increasing over time, possibly).Unlike the case of Figure 8 where arrows F2 were present, Figure 10 indicates, for the fourth phase P3, a heat transfer from the assembly mold 20 to the photovoltaic module 10 (this heat transfer therefore taking place in a direction opposite to the case already described where a thermoplastic resin was used) shown diagrammatically by the arrows FO, in the same way as in phases P1 and P2 of the same process. Furthermore, as in the case of Figure 8, the mechanical pressure (arrow F1) continues to be exerted by the assembly mold 20 throughout the fourth phase P3. The mechanical pressure that is applied while the two mold parts 22, 24 of the assembly mold 20 are maintained at the nominal temperature or undergo an increase in temperature, can be equal to the mechanical pressure F1 exerted during phases P1 and P2 or be different depending on the needs.

[0219] Finally, with reference to Figure 10, the fifth phase P4 can then begin, this phase P4 corresponding to the implementation of step E4 of opening the assembly mold 20, in which the assembly mold 20 passes from the closed configuration to the open configuration. Unlike the arrangements described previously in connection with Figures 7 and 8 in the case of the use of a thermoplastic resin, the use of a thermosetting resin implies, as shown in Figure 9, that the temperature of the assembly mold 20 and of the stack is reduced during the fifth phase P4. This is the reason why, in the fifth phase P4, the curve illustrated in Figure 9 is in the form of a profile decreasing over time, for example in a rectilinear manner.

[0220] During the fifth phase P4, the two mold parts 22, 24 undergo not only the temperature reduction mentioned in the previous paragraph, but also a relative separation by translation and / or rotation, until they are separated from each other by a distance strictly greater than the value of the predetermined air gap 26. In this relative separation of the mold parts 22, 24, the assembly mold 20 releases the mechanical pressure F1 previously exerted and the photovoltaic module 10 remains in the previously obtained shape, apart from a potential elastic return phenomenon. NOMENCLATURE

[0221] 1: photovoltaic module (state of the art)

[0222] 2: front face (state of the art)

[0223] 3: encapsulating assembly (state of the art)

[0224] 3a: front layer (state of the art)

[0225] 3b: back layer (state of the art)

[0226] 4: photovoltaic cells (state of the art) 4a: front face of the cells (state of the art) 4b: back face of the cells (state of the art)

[0227] 5: rear face (state of the art)

[0228] 6: connecting conductors (state of the art)

[0229] 7: junction box (state of the art)

[0230] 10: photovoltaic module

[0231] 12: first layer

[0232] 14: second layer

[0233] 16 photovoltaic cells

[0234] 18: encapsulating assembly

[0235] 181: encapsulation material

[0236] 182: encapsulation material

[0237] 20 assembly mold

[0238] 22: first part of the mold

[0239] 220: first impression of the assembly mold

[0240] 222: first seal

[0241] 232: atmospheric vents

[0242] 24: second part of the mold

[0243] 240: second impression of the assembly mold

[0244] 242: second seal

[0245] 26: predetermined air gap

[0246] 28: initial stacking

[0247] 30: cavity

[0248] 32: power input

[0249] 34: first draining matrix

[0250] 36: evacuation exit

[0251] 38: second draining matrix

[0252] PO: first phase P1: second phase

[0253] P2: third phase

[0254] P3: fourth phase

[0255] P4: fifth phase

[0256] E1: step of placing the initial stack in an assembly mold

[0257] E2: Resin transfer molding step

[0258] E3: hardening stage of the injected resin

[0259] E4: assembly mold opening step

[0260] E20: resin heating step

[0261] E21: step of lowering the pressure prevailing in the cavity

[0262] E32: Initial stack heating step

[0263] E22: step of injecting the resin into the cavity

[0264] FO: heat input to the stack

[0265] F1: mechanical pressure

[0266] F2: heat transfer from the photovoltaic module to the assembly mold

[0267] F3: resin injection

[0268] F4: air depression

[0269] F5: flow of resin into the first drainage medium

[0270] F6: resin flow into the cavity and into the stack

[0271] F7: flow of resin into the second drainage medium

[0272] D1: first direction

[0273] D2: second direction

Claims

CLAIMS 1. Method for manufacturing a photovoltaic module (10) where the photovoltaic module (10) comprises: a first layer (12) formed in a first composite material, transparent, intended to form a front face of the photovoltaic module (10) and to receive a luminous flux, a second layer (14) formed in a second composite material and intended to form a rear face of the photovoltaic module (10), and at least one photovoltaic cell (16) located between the first layer (12) and the second layer (14), the manufacturing method comprising the following steps: E1) placing an initial stack (28) in an assembly mold (20), where the initial stack (28) comprises the superposition of the following elements: at least one first dry reinforcement intended to belong to the first layer (12) and to enter into the composition of the first composite material, said at least one photovoltaic cell (16), at least one second dry reinforcement intended to belong to the second layer (14) and to enter into the composition of the second composite material, the initial stack (28) being such that the plurality of photovoltaic cells (16) is located between the at least one first dry reinforcement and the at least one second dry reinforcement,the assembly mold (20) having an ability to vary between an opening configuration and a closing configuration and comprising a first rigid mold part (22) delimiting a first imprint (220) having a shape complementary to the shape of the first layer (12) and a second rigid mold part (24) delimiting a second imprint (240) having a shape complementary to the shape of the second layer (14), the first mold part (22) and the second mold part (24) being such that, in the closing configuration of the assembly mold (20), the first mold part (22) and the second mold part (24) are spaced apart by a predetermined air gap (26) preferably greater than or equal to the thickness of the initial stack (28), and delimit between them a closed cavity (30) capable of receiving the initial stack (28), E2) resin transfer molding, in which a resin in the liquid state is injected into the cavity (30) in such a way that the resin passes through the at least one first dry reinforcement and through the at least one second dry reinforcement, E3) hardening of the resin injected in step E2, step E3 being carried out by a suitable adjustment of the temperature prevailing in the cavity (30), depending on the nature of the resin, the combination of the at least one first dry reinforcement and the resin in the hardened state at the end of step E3 constituting said first composite material and the combination of the at least one second dry reinforcement and the resin in the hardened state at the end of step E3 constituting said second composite material.

2. Manufacturing method according to claim 1, wherein the initial stack (28) comprises at least one encapsulation material (181, 182), the initial stack (28) being such that the at least one encapsulation material (181, 182) is located between the at least one first dry reinforcement and the at least one second dry reinforcement, and wherein during step E2, the temperature of the resin is adapted as a function of the at least one encapsulation material (181, 182) so that the at least one encapsulation material (181, 182) undergoes at least partial melting under the effect of calories transmitted by the resin and converts the at least one encapsulation material (181, 182) into an encapsulating assembly (18) adhering on the one hand to the at least one photovoltaic cell (16) and on the other hand to the first layer (12) and / or to the second layer (14).

3. Manufacturing method according to any one of claims 1 or 2, in which the first imprint (220) has a first shape such that the first layer (12) is shaped according to a first left shape at the end of step E3 and the second imprint (240) has a second shape such that the second layer (14) is spatially shaped according to a second left shape at the end of step E3.

4. Manufacturing method according to any one of claims 1 to 3, in which step E2 comprises, after step E1, the following steps: E21) depression applied to the cavity (30) delimited by the assembly mold (20) in the closed configuration, relative to the pressure prevailing outside the cavity (30), E22) injection of the resin into the cavity (30) in a pressurized manner at a pressure strictly higher than the pressure prevailing in the cavity (30), step E22 being carried out after step E21.

5. Manufacturing method according to claim 4, in which step E2 comprises a step E20 of heating the resin carried out prior to the implementation of step E22.

6. Manufacturing method according to any one of claims 4 or 5, wherein in step E22, the injection of the resin is carried out in a directed manner in a preferential direction in which the resin preferentially circulates inside the cavity (30) delimited by the assembly mold (20).

7. Manufacturing method according to claim 6, in which the assembly mold (20) comprises at least one discharge outlet (36) in fluid connection with a system suction allowing a depression to be established in the cavity (30) delimited by the assembly mold (20).

8. Manufacturing method according to any one of claims 6 or 7, in which the assembly mold (20) comprises at least one supply inlet (32) in fluid connection with a supply system making it possible to inject the resin towards the cavity (30) delimited by the assembly mold (20).

9. Manufacturing method according to claims 7 and 8, in which at the end of step E1, the at least one feed inlet (32) and the at least one discharge outlet (36) are located on either side of the initial stack (28) in a first direction (D1) oriented in said preferred direction.

10. Manufacturing method according to claim 9, in which the assembly mold (20) comprises at least one first draining medium (34) into which the at least one feed inlet (32) opens, said first draining medium (34) ensuring drainage of the resin in a second direction (D2) oriented transversely to the first direction (D1).

11. Manufacturing method according to claim 10, in which the assembly mold comprises at least one second draining medium (38) into which the at least one evacuation outlet (36) opens, said second draining medium (38) ensuring drainage of the resin in a second direction (D2) oriented transversely to the first direction (D1).

12. Manufacturing method according to any one of claims 4 to 11, wherein in step E21, the pressure established in the cavity (30) is between 0.5.10 5 Pa and 1.10 s Pa.

13. Manufacturing method according to any one of claims 4 to 12, in which during step E22, the injection of the resin is controlled so that the pressure prevailing in the cavity (30) delimited by the assembly mold (20) is between 2.10 5 Pa and 50.10 5 Pa.

14. A manufacturing method according to any one of claims 1 to 13, wherein the resin is a thermoplastic resin.

15. Manufacturing method according to claim 14, in which step E3 comprises a step of lowering the temperature of the stack resulting from step E2 compared to the conditions present during step E2.

16. A manufacturing method according to any one of claims 1 to 13, wherein the resin is a thermosetting resin.

17. Manufacturing method according to claim 16, in which step E3 comprises a step of maintaining or increasing the temperature of the stack resulting from step E2 relative to the conditions present during step E2.

18. A manufacturing method according to any one of claims 1 to 17, wherein the first mold part (22) and the second mold part (24) of the assembly mold (20) exert, on the stack, mechanical pressure (F1) during all or part of step E2 and during all or part of step E3.

19. Manufacturing method according to claim 18, wherein the mechanical pressure (F1) is between 90.10 5 Pa and 150.10 5 Pa, and more particularly equal to 90.10 5 Pa, or equal to 150.10 5 Pa.

20. Manufacturing method according to any one of claims 1 to 19, comprising a step E4 of opening the assembly mold (20) in which the assembly mold (20) passes from the closed configuration to the open configuration, step E4 being implemented after step E3.

21. Manufacturing method according to any one of claims 1 to 20 in which during step E1, the initial stack (28) further comprises the superposition of a junction box (7) intended to receive wiring necessary for the operation of the photovoltaic module (1).

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